Thread: Do ECUs self learn whilst driving

Originally Posted by nobbyclrk

Basically the ECM ignores the feedback from the Oxygen (nernst cell) sensors. Closed loop the sensor will signal the ECM weather the mixture is rich or lean and the ECM will react accordingly. So
Sensor indicates mixture is rich - ECM leans off fuel injected.
Sensor will now indicate mixture is lean - ECM now adds fuel.
And so it goes on, preferably no less than 10Hz (narrow band sensor).
A wide band works totally different. Basically two narrow band put togeather but one cell used as a pump.

I'm assuming these codes won't clear or just return soon after starting?

Check your power to coil 3/8. And with a LED tester on the switch side at the ECM. Although a flashing LED will not prove the switch is valid. But no switch will prove it won't work.

Same deal with 2 and 4 injectors. (P0204 and P0202)
And injector 4 (poss short) (P0271)

Ignore all Oxygen sensor codes at the moment. The ECM can live without that.

P135??????? Not sure about that.

These are symptoms not faults (P0300 P0302 and P0304).

I haven't looked into P1000 or P1300 yet.

Check out those injector and coil circuits and drivers(best you can) and you're be half way there.
But treat with caution when testing, the ECM may shut the injector driver down if it detects misfires (you may need to clear the codes before testing) on the cylinders to save the cat. But power should still be at the ECM switch side.
For a wild guess I would think the loom has melted/shorted somewhere.

One other thought is the state of the gas electronics system????? Could that be causing problems???????

the same lumpiness and miss on Petrol and same on LPG
I'm going to have to go over the loom and have a look at connections etc.

Originally Posted by PhilipA

While looking for whether the Thor was lambda all the time I came across this technical description of the Motronic 5.2.1 which may help you.
It still doesn't specify whether Lambda all the time but I recollect it from somewhere. Anyway its pretty unimportant.

p38arover.com/rover/p38a/Engine.../BOSCH_521_Systems.pdf

Regards Philip A

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